Pismo Needs the Reset Button Pressing Before it Boots

[Innes]

Hi all, im wondering if anyone might be able to make any suggestions regarding a 400mhz Pismo I have. As the title suggests, it boots so long as its plugged in at the mains and the reset button that sits among the ports has been pressed for a bit.

The obvious first thing to do was to disconnect the dead pram battery however that hasn't soulved it.Can anyone suggest what I might be able to try next?

Many thanks

 

[Compgeke]

Try replacing the dead battery.

 

[FacnyFreddy]

Dead battery.... your pram and main battery are toast.

Removing the Pram altogether will probably all you need. Then you MIGHT be able to get a (small/weak) charge on the main battery.

 

[Innes]

Just to re-iterate, I'v unplugged the PRAM already, its not connected.

The main battery is a replacement and capable of about 2 hours of charge so I don't think its that

 

[beachycove]

If you have a good main battery, chances are that the backup battery can be rehabilitated. They are very long lived. Reconnect it, if possible while the machine is "alive", and leave to charge for a day or so.

The Pismo, like some other PowerBooks, is known for not booting with a drained backup battery, which presumably has to do with power management — and this could explain what you are seeing happen when pressing the reset button.

 

[AichEss]

A properly operating Pismo will start with the PRAM battery disconnected with any condition of live, dead or missing main battery.

My go-to fix for what you describe is to disconnect the computer from the AC power, remove the main battery, and just let it sit for a day or so. You can push the start button &/or the PMU switch to drain the capacitors as much as possible.  (That also gives you the warm feeling that you are participating in the fix) Then just plug it in and start it up.

I assume you've done a PRAM Zap. Yeah, I know the PMU reset is supposed to do the same thing; IMO it doesn't.

I sincerely doubt that you can rehabilitate the backup battery. It's not rechargeable.

 

[beachycove]

I sincerely doubt that you can rehabilitate the backup battery. It's not rechargeable.

Actually, it is. Typically, the Pismo contains a set of these: https://industrial.panasonic.com/ww/products/batteries/primary-batteries/lithium-batteries/coin-type-rechargeable-lithium-batteries-vl-series/VL2330 .